1. Field of the Invention
The present invention relates to diagnosing whether a xerographic machine is running within specification during large printing jobs. In particular, the invention relates to inserting periodic test patterns into a large production print job and separating the printed test pattern from the printed production print job before the printed production print job is bound.
2. Description Of Related Art
During the printing of long jobs, especially those with color-critical output, it is often desirable to view diagnostic test patterns. These patterns allow the press operator to ensure that the press is operating within specification and that output will match proofs or prints from other devices. This procedure is fairly straightforward in the world of offset presses. Diagnostic test strips are printed on the edges of press sheets. There are access points on the press that allow sheets to be retrieved during the printing process. These sheets can be measured to check the current performance of the press.
In digital production printing, multipage documents are being produced and delivered via closed paper paths to finishing devices that do not allow convenient access to printed output until the printing process is complete. Furthermore, in most cases, sheet-fed digital presses image onto a paper size equal to that of the desired document. Thus, there is no non-document area on the sheets on which to place diagnostic patterns.